Another approach is to assign some values for x and y.

Let's say that x = 5 and y = 2
This means R = 3 and S = 10

We must determine the value of (x - 2)(y + 2)
Plug in x = 5 and y = 2 to get: (x - 2)(y + 2) = (5 - 2)(2 + 2) = (3)(4) = 12

Now take each answer choices to see which one gives us an OUTPUT of 12.

A. R + S - 4 = 3 + 10 - 4 = 9. ELIMINATE

B. R + 2S - 4 = 3 + 2(10) - 4 =19. ELIMINATE

C. 2R - S - 4 = 2(3) - 10 - 4 = -8. ELIMINATE

D. 2R + S - 4 = 2(3) + 10 - 4 = 12 KEEP

E. R + S = 3 + 10 = 13. ELIMINATE

Answer: D

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